Design and Assembly of SPT-3G Cold Readout Hardware

Journal Article · 24 May 2018 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/s10909-018-1965-5· OSTI ID:1481277

Avva, J. S.; Ade, P. A. R.; Ahmed, Z.; Anderson, A. J.; Austermann, J. E.; Thakur, R. Basu; Barron, D.; Bender, A. N.; Benson, B. A.; Carlstrom, J. E.; Carter, F. W.; Cecil, T.; Chang, C. L.; Cliche, J. F.; Cukierman, A.; Denison, E. V.; de Haan, T.; Ding, J.; Dobbs, M. A.; Dutcher, D. ; Elleflot, T.; Everett, W.; Foster, A.; Gannon, R. N.; Gilbert, A.; Groh, J. C.; Halverson, N. W.; Harke-Hosemann, A. H.; Harrington, N. L.; Hasegawa, M.; Hattori, K.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Hori, Y.; Huang, N.; Irwin, K. D.; Jeong, O. B.; Jonas, M.; Khaire, T.; Kofman, A. M.; Korman, M.; Kubik, D.; Kuhlmann, S.; Kuo, C. L.; Lee, A. T.; Lowitz, A. E.; Meyer, S. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Nishino, H.; Noble, G. I.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Posada, C. M.; Rahlin, A.; Rotermund, K.; Ruhl, J. E.; Saunders, L. J.; Sayre, J. T.; Shirley, I.; Shirokoff, E.; Smecher, G.; Sobrin, J. A.; Stark, A. A.; Story, K. T.; Suzuki, A.; Tang, Q. Y.; Thompson, K. L.; Tucker, C.; Vale, L. R.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Yoon, K. W.; Young, M. R.

The third- generation upgrade to the receiver on the South Pole Telescope, SPT- 3G, was installed at the South Pole during the 2016- 2017 austral summer to measure the polarization of the cosmic microwave background. Increasing the number of detectors by a factor of 10 to 16, 000 required the multiplexing factor to increase to 68 and the bandwidth of the frequency- division readout electronics to span 1.6- 5.2 MHz. This increase necessitates low- thermal conductance, low- inductance cryogenic wiring. Our cold readout system consists of planar thin- film aluminum inductive- capacitive resonators, wired in series with the detectors, summed together, and connected to 4K SQUIDs by 10- mu m- thick niobium- titanium ( NbTi) broadsidecoupled striplines. Here, we present an overview of the cold readout electronics for SPT- 3G, including assembly details and characterization of electrical and thermal properties of the system. We report, for the NbTi striplines, values of R = 10 L = 21 +/- 1 nH, and C = 1.47 +/-. 02 nF. Additionally, the striplines' thermal conductivity is described by kA = 6.0 +/- 0.3 T 0.92 +/- 0.04 mu W mm K - 1. Finally, we provide projections for cross talk induced by parasitic impedances from the stripline and find that the median value of percentage cross talk from leakage current is 0.22 and 0.09% from wiring impedance.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Science Foundation (NSF); Gordon and Betty Moore Foundation; Canadian Institute for Advanced Research (CIFAR); USDOE Office of Science - Office of High Energy Physics; Natural Sciences and Engineering Research Council of Canada (NSERC)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1481277
• Journal Information: Journal of Low Temperature Physics, Vol. 193, Issue 3-4; ISSN 0022-2291
• Publisher: Plenum Press
• Country of Publication: United States
• Language: English

Related Subjects

SPT-3G
cosmic microwave background
frequency-division multiplexing